Looks great! I have the same tank and it's running great - I had to plumb the thing with a Herbie myself but it works well enough. I don't think you really need a mixing station - I just mix mine in a 7 gallon bucket right next to it and do a 6 gallon water change every week. I have the RO all under the kitchen sink and going into a 5 gallon with a float valve (Also allows for nice RO water for the humans).
This all seems very well planned. Good luck.
This all seems very well planned. Good luck.